It wont be a bad effect, if anything a good one. You need the same strength and ability to swing a golf club and a baseball bat. As myself, I golf and i use to play baseball and my golf swing helped me alot with baseball.
Yes, they are designed to give you stability during the swing.
Shoes can make a major difference in your golf game, and with so many types out there on the market you definitely can find something...
Well, if by "back swing", you refer to the rest of your swing after hitting the ball... then it's probably down. Also, I've never seen someone hit the ball away from the hole to make it go towards...
I have encountered this problem. I recommend making sure your head is down, tee up the ball a little higher for practice, and making sure to keep tour front arm straight.